Presser plate for book stitching machines



March 26, .1935. I c, SCHRAMM 1,995,754

PRESSER PLATE FOR BOOK STITCHING MACHINES Filed Feb. 15, 1934 Patented Mar. 26, 1935 PRESSER PLATE FOR BOOK STITCHING MACHINE CarlSchramm, North Coventry, Conn, assignor to The Smyth Manufacturing Company, Hartford, Conn., a corporation of Connecticut Application February 13, 1934, Serial No. 711,058

6 Claims.

This invention relates to machines for stitching together the folded edges of book signatures that are successively fed to the stitching means, of the type which have reciprocating needles and hooks that operate fromabove the folded edges, and loopers and punches that operate from below and between the leaves of the signatures. These machines hav e presser plates that level the backs of the signatures as they are fed to stitching position and resist the upward thrust of the punches which pierce the holes for the needles and hookswhich plates also act to guide the needles and hooks asthey descend and pass through the pierced holes in the folded edges of the signatures.

Book stitching machines of this character have been provided with means for severing the stitching threads between the last signature of one book and the first signature of the following book, but in all such cases the means for selecting and severing the threads to be cut have been in the nature of appliances, that is, special mechanisms which are applied to and used in connection with the standard elements of the stitching machine.

The object of the instant invention is to simplify, cheapen and make more eflicient the thread cutting means of such machines, and this is accomplished in the present instance by so constructing the presser plates themselves that they not only act to level the folded edges of the signatures, resist the thrust of the punches and guide the needles and hooks, but also act to, at the proper times, sever the threads in such manner that the formation of an extra locking stitch between the last signature of one book and the first signature .of the following book is avoided, and the application of special, or additional, or supplemental, thread selecting and severing means is eliminated. v

The foregoing object is attained by dividing each presser plate into two sections, one section of each plate, that which has a perforation for the passage of a hook andthe hook punch, being mounted in fixed position, and the other section of each plate, that which has slots for the passage of a needle and the needle punch, being movable at predetermined times laterally with relation to the path of the needle, the latter section also .having means for cutting the thread.

to be severed. 4

In the accompanying drawing Fig. 1 is a front tive positions of the needles, hooks, punches and loopers, to the presser plates.

Fig. 2 is on larger scale a transverse section through some of the presser plates showing the needles, hooks, punches and loopers in another relation.

Fig. 3 is a vertical section of the signature carrying saddle and the movable section'of a presser plate, showing a needle, looper and punch.

Fig. 4 is a top view of some of the presser plates. 7 Fig. 5 is a view of the under side plate.

The stitching machine indicated in Fig. 1 of the drawing has eight needles 1 and eight hooks 2 that are reciprocated above and through eight presser plates 3 by the well known means.. Cooperating with the needles and hooks below the presser plates are eight loopers 4 which at the proper times are moved laterally, and sixteen punches 5 which are reciprocated for piercing holes in the signatures for the passage of the needles and hooks, the loopers and punches being carried in a swinging V-shaped feed saddle 6 and actuated at the proper times by the usual mechanisms. 7

The number of needles, hooks, punches, loopers and presser plates is immaterial to the invention, the number used depending upon the number of stitches to be made and their adjustment depending upon the length of the stitches to be made, there of course being a needle hok,.needle of a presser punch, hook punch, looper and presser plate for each stitch.

In carrying out the instant improvement each presser plate consists of two complementary sections 7, '8. The presser plate section 8 has a perforation 9' which permits the passage through it of a hook 2 and it is fastened to the under side of the presser plate bar ill in a permanent position. The presser plate section 7 which has slots -11 for the passage through it of a needle, is fastened to a bar 12 that is capable of reciprocation in the under side of the presser plate bar and that connects all of the movable sections of the plates. The bar 1-2 may bemoved first one way and then after a dwell the other way by a the fixed section of a presser plate, and the slot v throughwhich the needle reciprocates depends upon the adjustment of the needle and upon the location at the time, of the movable section of the presser plate. As illustrated in Fig. 4 of the drawing, the needle would reciprocate through the slot and when the movable section of the presser plate is moved transversely away from the fixed section the needle would reciprocate through the slot 16 and of course upon such movement of the plate the thread carried by the needle would be looped over the division 17 between the slots. The shift first one way and then the other way of the movable sections of the presser plates takes place immediately following the stitching of the last signature of each book.

Attached to the under face of each movable section of the presser plates is a series of V- shaped blades 18, the cutting edges of which increase in width toward the rear. Threads looped over the divisions between the needle slots are drawn back as the signatures are stitched until they are severed by the tapering edges of the cutter. This however does not occur until several signatures have been stitched after the loops have been formed, and thus the threads will not pull out or the signatures loosen when those of one book are separated from those of the following book.

By forming the presser plates in complementary separable sections, according to present improvement, special, additional, or supplemental attachments are avoided, for each plate acts to level the backs of the signatures, to guide the needle, hook and punches, to resist the thrust of the punches as they pierce the signatures, and also to out such threads as are required without allowing any loosening of the stitches.

The invention claimed is:

1. The combination with the needles, hooks, loopers and punches of a book stitching machine, of presser plates each of which plates comprises two sections of substantially equal area and thickness a fixed section with a hook and punch guiding opening and a section separable horizontally from the fixed section said movable section having needle and punch guiding openings, means attached to and movable with said movable sections for severing thread looped over divisions between the needle openings, and means for shifting back and forth said movable sections.

2. The combination with the needles, hooks, loopers and punches of a book stitching machine, of presser plates adapted to level the backs of the signatures and resist the thrust of the punches, each of which plates comprises two sections of substantially equal area and thickness a fixed section with a hook and punch guiding opening and a section separable horizontally from the fixed section said movable section having needle and punch guiding openings, means attached to and movable with said movable sections for severing thread looped over a division between said needle openings, and means for shifting back and forth said movable sections. 3. The combination with the needles, hooks, loopers and punches of a book stitching machine, of presser plates each of which plates comprises two separable sections of substantially equal area and thickness a fixed section with a hook and punch guiding opening and a section movable in the same horizontal plane as and toward and from the fixed section, said movable section having needle and punch guiding openings, means attached to and movable with said movable section for severing thread looped over a division between said needle openings, and means for shifting back and forth said movable sections.

4. A presser plate for book stitching machines which comprises two transversely separable sections of substantially equal area and thickness one section adapted to be fixed in position and provided with a hook and punch guiding perforation, and the other section adapted to be transversely separated therefrom and provided with needle and punch guiding openings also means for severing thread looped over a division between said openings through the latter section.

5. A plate for leveling the backs of signatures fed to the stitching means of book stitching machines which plate comprises two sections of substantially equal area and thickness one section adapted to be fixed in position and provided with a hook and punch guiding perforation, and the other section independent thereof and adapted to be transversely separated therefrom and provided with needle and punch guiding openings also provided with blades for, severing thread looped over a division between said openings through the latter section.

6. A presser plate for book stitching machines which comprises two independent but complementary sections of substantially equal area and thickness separable with relation to each other in the same horizontal plane, one section having hook perforations and the other section having needle guiding slots and attached thread cutters.

CARL SCHRAMM. 

